The correct answer is A. ENIAC.
ENIAC, or Electronic Numerical Integrator and Computer, was the first general-purpose electronic computer. It was built at the University of Pennsylvania’s Moore School of Electrical Engineering and was completed in 1946. ENIAC was used to calculate ballistics tables for the U.S. Army during World War II. It was also used for a variety of other scientific and engineering calculations.
UNIC, or Universal Automatic Computer, was an early mainframe computer developed at the University of Manchester in the United Kingdom. It was completed in 1951 and was one of the first computers to use magnetic tape for storage. UNIC was used for a variety of scientific and engineering calculations.
BRAINIA, or Brainiac, was an early mainframe computer developed at the University of Illinois at Urbana-Champaign. It was completed in 1952 and was one of the first computers to use a transistorized design. BRAINIA was used for a variety of scientific and engineering calculations.
FUNTRIA, or Functional Transform Analyzer, was an early mainframe computer developed at the University of California, Los Angeles. It was completed in 1953 and was one of the first computers to use a core memory. FUNTRIA was used for a variety of scientific and engineering calculations.
ENIAC was the first general-purpose electronic computer, and it was used for a variety of scientific and engineering calculations. UNIC, BRAINIA, and FUNTRIA were also early mainframe computers, but they were not as widely used as ENIAC.